The title may lead you to think we are talking about people who manage pasture or have access to wide areas of rangeland. In fact, we are talking about people whose parents and grandparents were nomadic pastoralists that ranged flocks of animals across vast areas of land with the changing of the seasons. Rangelands in the Middle East were traditionally managed by tribal councils. This form of community-managed rangeland, called the Hima system (PDF), was one of the longest standing and most successful forms of rangeland management in known history. However with the arrival of nation states, the tribal systems of regulation were subordinated to state governments, run by bureaucrats living in the cities. Borders were drawn on the map, cutting across traditional patterns of land use and seasonal migration. Land was nationalised and tribal structures disempowered. In the case of Palestine it was worse, because much of the population was physically displaced, first in 1948 then again in 1967. Many of the latter wave of refugees who were pushed into Jordan have never gained citizenship. Of course the Palestinians in Jordan are now in quite a good situation compared to the Palestinians left in Palestine, but they still lack control over the land resource and hence have no chance to manage broad-scale rangelands as their forefathers did.

The average family compound may be 400-800m2. The rest of the landscape is government land which is effectively commonage. So in such situations it is the “tragedy of the commons” all over. Most of the high quality land in the Jordan Valley is given to investors for irrigated agriculture. What remains is the rocky west facing slopes. There may be some growth of herbage for a couple of months in late winter/early spring, but it is heavily contested by the local Bedouin tribes, as well as anybody else who has animals in the area. There are no longer any regulatory structures to decide who grazes what — it’s just “grab what you can while you can!” Hence anything without a fence around it has been heavily depleted and denuded. That is why people have to import grain from Ukraine to feed their animals for the rest of the year.

So what we are looking at here is not really a rangeland management system, which would require massive resources, real political influence and extensive community cooperation on a wide scale. What we are really talking about here is designing a small scale intensive system that allows a single family to economise on the costs of feeding their sheep in their cramped little domestic compound. And it really ends up having a lot more to do with sewage than you may have expected from the title!

So the design brief is: design a household-scale domestic waste-water treatment and land-application system which will:

Treat all the household water from a typical Jordan Valley home to a suitable standard (according to Australian regulations) that is safe for both watering livestock and performing surface irrigation of fodder crops, without posing a health risk to either the system operators or the public in general.

Will fit into an average back yard in the town of Jawfah, Al-Balqa province, Jordan.

Will produce enough edible (to small ruminants) biomass to significantly affect the domestic economics of the owners who operate it due to a reduction in the need to purchase commercially grown feed.

Can be constructed with a realistic budget to be fundable by a small grant from a local organisation or donations from individuals.

Will require a minimum in technical knowhow and labour for establishment, maintenance and operation.

So, we will go through these objectives one by one.

1. Waste water treatment

The Use of Reclaimed Water Guidelines (PDF) distinguishes between four quality categories of treated waste water, which are of suitable standard for different downstream uses. The criteria for these classes are as follows.

Table 1

The document goes on to state that for livestock husbandry activites, including both animal drinking water and irrigation of pasture, reclaimed water should be of Class B quality.

Hence our system has to put the domestic waste water through both secondary treatment and disinfection processes before it is safe to use downstream. The “On-Site Sewage and Wastewater Management Strategy” (Lismore City Council, 2013 — PDF) defines secondary treatment as follows:

“Secondary Treatment” aerobic biological processing and settling or filtering of effluent received from a primary treatment unit. Effluent quality following secondary treatment is expected to be equal to or better than 20 mg/L BOD5 and 30mg/L suspended solids.

BOD means “biological oxygen demand”. It refers to the amount of oxygen that would be consumed by micro-organisms in order to break down all of the organic material in a litre of the water in question through aerobic processes. If waste water has a high BOD there will be rapid depletion of the dissolved oxygen in it, as the organic materials are consumed by aerobic micro-organisms. In order for this oxygen to be replaced it must diffuse into the water from the surface. If the water has a small surface area and is not moving this diffusion will usually be slow, hence the water will become anaerobic, meaning it has no oxygen left in it. Anaerobic conditions lead to a different micro-biology proliferating in the water, which tends to produce far more toxic and smelly compounds. Hence a high BOD is bad news.

“Suspended solids” refers to non-dissolved particles floating in the water.

But before going through secondary treatment, waste water has to go through “Primary Treatment” — the separation of suspended material from wastewater by settlement and/or floatation prior to discharge to either a secondary-treatment process, or to a land application system. (Ibid.)

Primary treatment should be done in a septic tank. It is worth noting that most rural homes in Jordan are not connected to any sewerage system. We observed that most houses in Jawfa use a cesspit. A cesspit is basically a big hole in the ground (the ones we have seen in Jawfa are approximately 3 x 3 x 3m), lined on the sides with cement block with gaps left between the blocks, and covered over with a concrete slab. There is an inflow pipe but no outflow. Anaerobic breakdown in the cess-pit will gradually liquefy and dissolve any solid organic materials in the waste water. The water along with these soluble breakdown products will infiltrate into the ground. Anaerobic breakdown does not however reduce the dissolved nutrients and high nitrate levels seeping into the ground-water and can pollute it. In severe cases this can be hazardous to human health. Cesspits are no longer permitted under most developed country health and safety regulations and most have now been replaced by septic tanks, where connection to the sewerage system is not an option.

Septic tanks are sealed tanks (which don’t leak into the groundwater). They are large enough to hold all the waste-water from the household for a period of not less than 24 hours. They have an inflow and an outflow with an internal baffle wall, which has a small opening around 50cm below the surface. The baffle separates the tank into two chambers. After flowing into the tank, the vast majority of solid materials in the waste water will either float (as will oils and greases) on the surface, forming a scum, or sink to form sludge. Either way they are trapped in the first chamber. The high BOD of the liquid means it will quickly become anaerobic. The scum also seals the surface of the water, keeping it so. So septic tanks are anaerobic by definition. The solid materials trapped in the tank will undergo anaerobic breakdown into soluble compounds, which will escape from the tank in the effluent. Some solids that won’t break down any further will stay in the tank as sludge. The sludge needs to be emptied every few years when it builds up, and the tank needs extra capacity to store that sludge and still maintain a 24h retention time.

Where V/P/D is the volume of water used per person per day and NP is the number of users. The 1550 L is for sludge storage, based on the assumption that 1550 L of sludge is the amount that will accumulate in around three years, though this is somewhat variable and needs to be checked. The minimum allowable overall storage capacity is 2300L for a tank receiving all household waste water and 2050L for one receiving black water only.

So, how big a tank will we need in Jawfah? Well, the average Jordanian uses around 80L of water per day. But enquiries indicate that water usage in Jawfah may be somewhat more than that, in fact as high as 170L (an average Australian apparently uses 150L for comparison). It’s always best to look at the worst case scenario when planning, which in this case is the bigger number because more capacity means more materials and more budget! So assuming we have a water use of 170L/person/day and 5 people in the house:

Capacity = (170 x 5) + 1550 = 2400 L

In terms of dimensions, a septic tank should have a minimum depth of 1.5m, with a floor sloping 1:10 towards the inlet end. Longer is also better than wider. Hence if we set the internal width of the tank at 0.5m, and the baffle wall has a thickness of 15cm, in order to get a capacity of 2400L we need an internal length of 3.05m and a depth at the inflow of 1.96m. The baffle wall should be set at 2/3rds of the length of the tank from the inlet, so that the inlet chamber is twice the length of the outlet chamber. Ask me for the calculations if you want to check them!

Figure 2: Septic tank basic dimensions and layout

The effluent coming out from a septic tank is expected to have the following load of BOD, suspended solids, nutrients and pathogens:

Reed-beds are an increasingly popular type of secondary treatment device due to their aesthetic appeal, their reliable treatment performance capacities once the reeds are fully established, and their somewhat lower construction costs and maintenance requirements compared to other options. They are also passive devices not necessarily reliant upon power or pumps, and therefore economical to operate in the long term. Reed beds are usually required to be constructed from solid moulds such as plastic tanks or concrete troughs, concrete is preferred.

There are several different types of reed bed, but the one we are planning to use is a horizontal sub-surface flow constructed wetland. This type is optimal because it needs no pumps or moving parts and keeps the water below the surface of the gravel, reducing scope for mosquitoes or flies breeding in the waste water, or for contamination reaching up above the surface. This type of reed bed comprises a gravel medium through which the waste water flows between inlet and outlet, both of which are fixed below the surface of the gravel. Macrophytes (aquatic rooted plants such as reeds, rushes or sedges) are planted in the gravel and their roots grow down to form a network filling the spaces. The roots perform a physical filtering function. They also oxygenate the water, since macrophytes draw oxygen down into their root systems from the air above. Bacterial film also forms over the surface of the gravel and the roots metabolizing and breaking down organic compounds in the water.

Based on best scientific knowledge at the time a 7 day residence time was thought to produce a secondary treated wastewater (BOD 20mg/L, TSS 30mg/L) and reduce nitrogen by 50%. However, a recent study (Headley & Davison, 2003) has shown that approximately 5 days is required to reduce nitrogen by 50%. Seven days would still be required to produce a secondary treated effluent unless it is a grey-water reed bed where the residence time may be less than 7 days.

So using the basic “7 day rule of thumb” we can calculate the area of reed bed we need given our estimated water use:

Area = (V / DP)

Where V is the volume of water used in 7 days, D is the depth of the water in the reed bed and P is the porosity of the gravel medium (the proportion of the total volume not taken up by the gravel itself). Our model household in Jawfa with 5 people using 170L each per day uses a full 6000L per week. If we set the reed bed depth at 50cm, using 20mm aggregate gravel which has a porosity of 0.4, we will get the following:

Area = 6 / (0.5 x 0.4) = 30m2

Some more research into reed beds threw up some quite tricky calculations by which we can test the assumption that 7 days will give a low enough BOD and TSS to be secondary water. In both cases, at the ambient temperatures in Jawfa, 30m2 is more than enough to treat 6000L per week and get better then required BOD and TSS, even during the coldest month, January. Again, if you want to see (and check) these calculations they are available on request.

Furthermore, if we refer back to The Use of Reclaimed Water Guidelines (EPA Victoria, 2003) (Table 1), helminth reduction was stated as a necessary criterion for the water to be considered as Grade B reclaimed water, suitable for watering animals and irrigating fodder crops. Helminths are parasitic flatworms. The treatment system needs to be effective at removing their eggs from the waste water so they don’t infect the animals drinking it.

Duncan Mara (2003) “Domestic Wastewater Treatment in Developing Countries” states that: “Helminth egg removal in the gravel bed of horizontal-flow wetlands is very efficient: Stott et al (1999*) found that all eggs were removed in a 100m long reed bed in Egypt, with most being removed in the first 25 m.”

Figure 3

Reed bed design should be such that all of the water is on the move through the medium at any one time. This can be achieved by using splitters on the inlets and outlets. However a better way is to use baffles, which force the water to flow on a longer path through the gravel medium. In-fact if we have a gravel medium of 30m2 surface area, we can force the water to pass along a 100m flow path, using baffles. If the whole bed is 10m x 3m, it can be split slices 30cm wide, ten of which run back and forth along the 10m length of the bed. If the baffles themselves are 10cm thick the total bed area will end up 10m x 4m. This design thus both fulfils the 7 day residence criterion for BOS and TSS as well as the 100m length criterion from removal of helminth eggs.

Figure 4

Effluent from the reed bed must now be disinfected to remove any remaining bacteria (which are not removed by the reed-bed). The most effective technique for this is UV radiation which leaves no chemical residues and only requires a small amount of electric power. UV disinfection kits are available for a few hundred dollars in western countries, so if not available locally, one can be purchased and imported for this project quite easily.

The smallest models are sufficient to handle the flow rate of our system which is only 0.6L/min on average.

Reclaimed water use

With the water now treated and disinfected to a Class B standard it can be used for watering the animals and growing fodder with a surface irrigation system. Water will gravity feed via pipe from the reed bed outflow box via the UV sterilizer to a collecting tank. The water stream will now be split into two parts, one for watering the sheep and one will be used for irrigating a fodder crop.

The sheep watering system is quite simple. It will be given priority over the irrigation in the use distribution. Water will gravity feed from the collecting tank to a trough. The water level in the trough is regulated by a ball valve which is protected under a cover at one end so the sheep can’t damage it. When the trough is full the ball valve shuts off the pipe so no more water flows in from the collection tank. When the collection tank fills a dosing siphon is triggered which diverts the full tank of water into the irrigation system all in one go.

Land application system

In order to keep the budget within reasonable limits and reduce the need for skilled technical maintenance, we want to avoid the use of pumps or moving parts as much as possible. Hence we have selected a low cost, low-tech, low pressure (gravity-fed) drip irrigation system. The KB-Drip System (KB stands for “Krishak Bandhu” which means the “farmer’s friend” in an Indian language, not sure which one) was developed in India by International Development Enterprises (IDE). The EDK kits can be customized to suit the land area coverage required and generally cost around $600/Ha, which comes to a mere $0.06/m2. There is a lot more information on these systems available here: Palada et Al. 2011 (PDF).

To estimate how much area coverage we would need for our system let’s consider how much treated waste water we need to “dispose of” each day. Our assumed weekly water use was 6m3 for a family of 5 in Jawfah. If we estimate 10% loss in evapotranspiration in the reed beds and treatment system generally, we have 5.4m3 left to deal with. Then we expect the sheep to drink 0.63m3 per week. So we have about 4.77m3 per week left, which is 682 litres per day.
The lateral drip lines in this system will be 10m long with drip emitters placed every 30cm. Hence a 10m line has 30 drip points. One drip point emits around 2.5litres/hour with 1m of head pressure. Hence 1 line will emit a total of 75 litres per hour. If we have 4 lines the system will use 300 litres per hour. The lines are spaced at 1m intervals and can irrigate a footprint of 1m width, so the area coverage of this system would be 40m2.

Well, how is this going to work when we only have 682litres per day? That is a good question. We use a dosing tank. The irrigated area has to be a bit downhill from the collection tank. The tank has a dosing siphon in it. This is a very clever device which does not let any water out of the tank until it fills up, but then when it is full it opens the outflow so that all the water can flow out in one “dose”. “Designing and Installing On-Site Wastewater Systems: A Sydney Catchment Authority Current Recommended Practice” (PDF) describes the “Flout®” which I guess is a compound of the words “float” and “out”:

Figure 5: The single Flout®

As effluent from the septic tank fills the dosing chamber, the Flout™ … is empty, buoyant, and floats on the surface. High quality, flexible connectors allow the Flout® to rise. When the effluent reaches the maximum level in the chamber, it spills into the opening in the top of the Flout®. This causes the Flout® to sink (Figure 14.7). The effluent now discharges through the pipe exiting the dosing chamber and doses the land application area. The chamber continues to empty down to the top of the Flout® (Figure 14.8). Then the Flout® empties and resumes floating to repeat another cycle.

Figure 6: More Flout®s

So if we have a dosing tank of say 350L volume fitted with a Flout®, each time the tank fills up the water will run out to the drip system in one dose. It will take 1 hour and a bit for the drip system to empty the tank, by when the head of the Flout® will be empty and it with start to float again not letting any subsequent inflow out of the tank till it fills up again. On this cycle the tank should fill up twice per day.

2. Fitting it all into a back yard in Jawfa

Lacking any real data on this, I will give you a rough estimate that a normal family compound in Jawfa is between 400 and 800m2. If the house, car park, associated buildings and the sheep house/pen take up ¾ of all this then we have 100 – 200m2 to play with. Based on the above we are using approximately the following for our systems:

System

Estimated total Area Usage (m2)

Septic tank

5

Reed bed

45

UV irradiation and dosing tank

1

Irrigation area

50

Total:

101

Note that there also has to be a difference in vertical elevation between the treatment systems and the irrigation area, ideally of at least 1m so that water can gravity feed into the drip system. Also there needs to be sufficient space to accommodate foundations, wall and baffle thicknesses, pathways, pipes etc. and for all structures, so these are upper-estimates of how much space would be required in total.

3. Feeding the Sheep

So, what will we grow using this 40m2 irrigated area? I would say it’s best to go with a heavy feeding perennial clumping grass like Napier/Elephant grass (Pennisetum purpureum) which is one of the most productive fodder crops there is. It can be slashed to harvest and re-grow from the base (without any need to re-seed) on a 90 day cycle. This will keep labor to a minimum. One clump of Napier per 60cm is enough since they get big and will be too crowded otherwise. On the intermediate points in the drip line we can put in perennial legumes like leucaena, sesbania or calliandra, which are great high protein fodders, especially the pods. These can be pollarded once a year to 1.5m high so they don’t shade out the Napier. The best time to pollard them would be in the autumn when it starts getting overcast.

In terms of actual kilos of biomass production, Napier grass has been reported to yield up to 85,000kg/Ha dry mass every 90 days with 2000mm rainfall when fertilized with 897kg/Ha of urea (Orodho 2006). This translates into a rate of nitrogen application of N of 98.7g/m2. We expect high levels of fertility in our treated waste water due to residual nitrogen and phosphorus in the water.

How much residual nitrogen do we expect?

Tabel 4 (taken from NSW, 1998 – PDF) indicates typical primary effluent contains 50 – 60 mg per litre of Nitrogen. If we expect the reed bed treatment to reduce this by 50% (Lismore, 2004) we should still have 20 – 30mg/L nitrogen in the reclaimed water. Recall that we are irrigating our land application with 682L/day of water. Hence in 90 days the total waste water applied will be 682 x 90 = 61,380 litres. At a rate of 20mg/L this water will contain a total of 1.22Kg of nitrogen which is distributed over 40m2. Hence this would translate to a rate of 30.96g/m2. This is about 1/3rd of the rate of fertilizer application used in study cited by Orodho (2006). We also expect to be able to apply composted sheep manure as a supplementary solid fertilizer. Potentially liquid bio-fertilizers could also be prepared and added into the dosing tank. So these will be able to make up the difference.

In terms of water, the study referred by Orodho (2006) used rain-fed production at 2000mm annual rainfall. The total water application over our irrigated area will come to around 1800L/m2/year. Interestingly the actual rainfall is around 200mm per year, meaning our plot should get about the same total amount of water per unit area as in the study.

So we should be able to yield high rates of production from Napier grass in a mixed planting with perennial legumes. If we can manage a yield of equivalent to 85,000kg/Ha in 90 days this would translate to a dry matter production rate of 8.5kg/m2 per 90 days, which would yield a total of 34kg/ kg/m2/year which is 1360kg/yr total from our 40m2 plot.

In terms of fodder substitution this is equivalent to 12.4% of the 10,950kg of grain fodder now fed to a flock of 30 sheep.
Then we also have the biomass yield of the reed bed. Burke (2011) indicates that Typha latifolia (cat tails or reed mace) can produce around 36,000kg/Ha dry matter per year. This is also good quality fodder if harvested continually. This would translate into 3.6kg/m2 dry matter, so 108kg/yr from our 30m2 reed bed. This would substitute another 1% of the fodder ration, giving a total of 13.4% substitution.

Looking back at our previous figures from Part I, this is expected to increase the annual profitability of the flock by 36.2% to a total of 1103 JD/year. This is a total increase of JD351/yr from the current situation, which is equivalent to the value of nearly-two extra sheep per year.

Right, well that gives us something to aim for in terms of output. Next we are going to consider how much it will cost to build all this….

Stay tuned for Part III.

~~~~~

Note: We will implement a system like this during an internship in May 2015. So if you want to be a part of that, click here for details. The internship will be half spent building the waste water system on a local household and half spent on the Greening the Desert “Sequel” site maintaining and expanding the systems in place there. Understandably, the PRI can only front funds for project we do on the site, so we are currently seeking partners to help support the project. Please contact me if you know anybody or any organisation that can help.

I’ll also be running a shorter, more general course on using Permaculture for development projects at the PRI Zaytuna Farm, Australia site, starting January 19, 2015.

Hi Alex, I found the design brief quite surprising. Pastoral farming has created these desert landscapes, so perhaps a different cultural approach to land use here is appropriate? I acknowledge that it can be much harder to do this … it appears much easier to try to come up with an engineering solution (although this may only put a sticky plaster over the wound, as it doesn’t address the underlying issues).

However, transformation of cultural approaches to land use has been achieved in some startling landscapes, such as the loess plateau in China – I’m sure you’ve seen John D Liu’s documentaries about these areas.

The design brief aside, I am an engineer who specialises in on-site wastewater systems integrating into permaculture/sustainable/terraquaculture landscapes. If your toilet waste is kept separate from your greywater, then you can use very low cost systems such as mulch basins to soak the greywater into the landscape, without additional filtration or treatment. An important feature of these very simple systems is that the nutrients in the greywater are available for plant growth, instead of being filtered or treated out. I avoid treatment systems & reedbeds as much as possible, because I want those nutrients going into the soil, where they can be used by plants.

A key question for me is: where does the water currently come from for watering the animals? Perhaps a flush toilet could be abandoned and this would provide sufficient water for the animals? If you can find another way to provide sufficient water for the animals, then you have the opportunity to abandon the complex, expensive system you’re proposing and do something much simpler…

Is terraquaculture an alternative way to hydrate the landscape besides swales? Is it mostly for cropping as opposed to planting trees? I have never heard of this but I am really intriqued. Could you recommend some introductory reading on this subject for a beginner? Thanks so much.

OK, I did some looking on https://www.permaculturenews.org and searched “terraquaculture and permaculture”. Two good articles come up with more websites to further look into this subject. You will find out a bit about terraquaculture, when it might be appropriate, and basically describing what it is. So for those who are new to permaculture like myself, maybe this will help.

Firstly, please read part 1 of the article where I explained we are trying to make Permaculture more relevant to the lifestyle of the local community rather than trying to socially re-engineer them to fit with our western preconceptions about how they should live. These people are a pastoralist culture. It’s in their blood, it’s what defines them. You refer to the Loess Plateau. What John D Liu doesn’t mention is that the project was funded by the World Bank to the tune of 150 million $US. That is some serious leverage… we just don’t have that resource to play with. And even if we did why is a pastoralism a problem? There is ample evidence that livestock can be not only sustainable but restorative when properly managed. What’s more, traditional pastoralism WAS properly managed by tribal societies before they were disempowered and dispossessed of their lands by nation states managed by urban bureaucrats. Please see: http://giscenter.isu.edu/research/techpg/nasa_intl/pdf/ch15.pdf AND http://www.managingwholes.com/downloads/overgrazing.pdf In fact it was the Phoenicians, Greeks and Romans who deforested the ME (http://www.eh-resources.org/wood.html) all agrarian societies. The people who destroyed the landscape were the people who built the cities. They chopped down all the trees to build their cities with, and then build ships and forge weapons to go and colonise other lands and steal their resources too… so blaming it on the shepherds is a bit unfair, I feel. It turns out that all Alan Savory did is find out that (like with so many other things) the way people used to do things before industrial capitalism and the nation state came along worked really just fine in the first place.

Now as for the system design, thanks for your advice and it is good logic. I did consider doing a compost toilet + GW system, which is after-all the usual Permaculture approach. But there are several reasons why I have chosen to go with what may be considered a more boring mainstream (excuse the pun) approach: a combined black + grey water and reed bed system feeding into a surface irrigation system. The first is that I want to get a foot in the door with these people. We are dealing with a society that has certain norms and values. Directly handling human waste, even if it is broken down, is not going to be culturally acceptable. Hitting them straight up with the idea that they will have to shovel a heap of their own droppings out of a cupboard in the ground every three months is not going to resonate well with your average Jawfa resident, I am sorry to say. If we take things with them one step at a time and start by showing them that they can use their domestic waste water to improve their living conditions, without altering their lifestyle, then we can start adding in other things around that. This is a pilot project. Once they see the benefits of the system functioning I am sure they will start getting receptive to more new ideas.

Hence dry composting toilets are out of the question for now. As for grey water, I am also not sure about what kinds of detergents and chemicals they will be using in the house. I want a system that is robust enough to work without the operators having to modify their lifestyle. Of course if they DO modify their lifestyle, great, but them not doing that should not mean that the project fails. Reeds are very robust, tolerant of toxins and good at immobilising and breaking them down. If we use grey water direct we may end up poisoning the plants we are growing to feed the sheep with. Salt build up in a hyper-arid environment is also a concern and my experience with mulch pits has not been very convincing to date.

Another issue I am somewhat weary of is the establishment. We are looking to get funding for this from NGOs based in Amman. Unfortunately to pull this off we also have to keep the bureaucrats happy, hence I want to make sure the specs fulfil western country standards (as well as local social protocols), since most urbanites in developing countries see the western model as what they should aim to emulate. Yes I know that is not the way it SHOULD, be but this is a pragmatic strategy not an ideological stance. What we want is to achieve something on the ground, so I have de-radicalised my approach as much as I can while still taking a step in the right direction. At the moment people are using cesspits. In any case reed beds produce reeds, which are fodder for the sheep and will end up going into the compost we add to the land application beds, so it all ends up in the soil in the end anyway…

Another thing I like about this design is that the users can chose to do anything else they want with the water, like making compost etc. and it will be safe for them to handle the water. If we want to make sure they don’t use it to wash the car we just have to make sure the system is down-hill from the car park!

Great plan and system you folks are putting together. Your undertaking isn’t an easy one but if anybody can pull this off you can. In anticipating part 3 when you’ll address cost I would like to suggest a possible funding source. First off I would form a cooperative with as many farmers as you can. For strength in numbers, shared goals, cut cost, easier to market end products, easier to raise funding etc. These are a proud people and they don’t want a handout just a hand up. Once the total coop cost are figured I would try Crowdfunding a low interest loan for 125% of project over a comfortable amount of time. With a successful project outcome this established source could be used on other projects.
I was also wondering if a “seed to fodder” system would work along side this. Could provide fresh feed during the winter months and increase production and profits. How ever you folks set this up I know it will work. Best of luck to you and keep it green…Rob

Thanks for pulling up the funding admin side of things. Well at the moment this is just a pilot, but if/once we can show it works, we are hopeful we will get wide-scale interest from the community and then setting up an association should be easy. Then we can get into revolving funds etc. At the moment we are seeking to get funding from a local NGO based in Amman. We have a contact with them through a previous student that did a PDC at the GD site last year, and we should run it as a PRI-NGO cooperation pilot project. If it works out we can look to get funds for scale up from bigger organizations including international NGOs. I work with a German Foundation funding water, WASH and Permaculture projects in Ethiopia using a similar model: develop a pilot with a bit of your own sweat, showcase the success then bringing in bigger donors and co-donors and progressively scale up. (I will post an article on the Ethiopian projects soon BTW.) However, we are open to anything that might work and should we need funds because the local NGO could not cover the full budget (for example) then crowd funding may be an option. I have to say, whenever I have tried crowd funding before it has gotten pretty miserable results, but if you think you can help make it work then that would be great.

You say: “But before going through secondary treatment, waste water has to go through “Primary Treatment” — the separation of suspended material from wastewater by settlement and/or floatation … Primary treatment should be done in a septic tank.”

That last statement is typical of conventional thinking — the tried and tested solution is the only conceivable one. Septic tanks are anti-ecological. They merely store the “waste” in preparation for it to be taken “away” (that mythical place to which all “waste” goes) instead of being converted into a beneficial form (the problem is the solution!) Basically, in the septic tank we are looking at an engineering solution to an ecological problem.

I’m not an expert on sewerage systems (I’m an ecologist by training and an ecological designer and writer by vocation). But I have designed and implemented a composting-based waste water treatment system costing less than €500 at our ecological study centre here in Northern Spain (website: http://www.abrazohouse.org)

I have been told by knowledgeable people that our treatment system is just as safe, if not safer, than a standard septic tank and leachfield; and of course, it’s much more ecological because we reuse ALL the nutrients from our wastewater on site.

Basically our “septic tank” is a standard dual chamber composting toilet into which the black water pipe empties. Since I’m skeptical about conventional engineering solutions, you could call it a “skeptic tank” if you like!

It has absolutely no pumps or moving parts, nothing that can break down. There is a bed of branches at the bottom to catch the solids. Then every couple of days you open the lid and scatter carbon-rich cover material (we use sawdust from a local carpentry shop — about 1 sack a month. I plan to use biochar once I can get a biochar production system up and running.) We also add wriggler worms and some finished compost as inoculate. That’s it. Every six months to a year you empty one of the chambers (which is now probably fully composted, but for safety should be emptied into a separate compost heap, ideally) and turn the pipe to direct the waste to the now empty chamber.

The greywater and the effluent from the composting chamber are treated in a straightforward mulch pit, of the kind recommended in the excellent book, Create an Oasis with Greywater by Art Ludwig (http://oasisdesign.net/). The name “reed bed” suggests it’s the plants that are doing the treatment, but this is incorrect. It’s the microorganisms in the mulch and the ground that are doing the work of treatment; the plants are just making use of the nutrients they liberate. They don’t have to be reeds, they can be any water-loving species (perhaps you should be looking at planting crops that can be sold or consumed directly to reduce dependence on livestock?) In our case we have a bunch of different stuff, including bullrushes, irises, alder, comfrey, and nettles (we didn’t plant them, they volunteered). I’m trying to find some bananas that will crop in our temperate climate…

Our system has been working fine for two years with absolutely no problems. We’ve even got the bonus of free tomato plants which sprout from the compost chamber (the lid is translucent). I have been intending to write up a description for permaculturenews.org, but I never seem to get round to it (if there is enough interest, I will do so!)

Based on my experience — which is limited to what I have described above — the system you propose is over-engineered for a single dwelling. Our filtration area is no more than about 5m2 and that is in a clay soil! Nonetheless the pond at the end of the system has NEVER filled with water because it all gets soaked up by the mulch or seeps into the ground. Of course, you may WANT a larger filtration area than is necessary, to spread the greywater more evenly.

So, I would suggest you implement something similar to our treatment system in Jordan. I don’t know what your budget is for the system you propose, but I suspect you could build 4 of the kind I describe for the same cost, because there are no fancy parts at all: just standard plastic pipes and a brick composting chamber with a lid, everything else is free.

Thanks for your perspective. What you are using is called a wet-composting toilet. It’s not that unconventional at all, in fact it is a system that has been authorised in Australia for a number of years. (see: http://www.dlg.nsw.gov.au/DLG/Documents/information/onsite.pdf p101). The problem with these systems is that the owners have to be committed to operating them. As I say, culturally, asking the people in Jawfah to handle their own solid wastes, even if they are broken down, is a big step to take all on one go. You are correct that a septic tank is just a holding tank which holds the liquid portion of the waste for 24hours. The solid components however remain in the tank and are broken down by anaerobic processes into soluble products which then pass out in the effluent. There is no reduction of nutrient load so all the nutrients still go on to the downstream systems, which in this system are fodder-producing reed beds and drip irrigated fodder producing beds. There is no infiltration trench in this system. For compost we have an ample supply of sheep manure which is far less controversial to deal with. There are also no pumps the whole thing is gravity fed. The only moving part is the dosing siphon which is just a floppy pipe with a box on the end. The UV lamp is the only technical item in the system and it has no moving parts. All that has to be done is change the light bulb every few years. (No jokes about indigenous people and light bulbs will be tolerated.)

Your system looks interesting, thanks for the info, but when you analyse it, other than the wet-composting instead of a sceptic tank you are basically doing the same thing we propose here, it’s just that we are using the downstream water for irrigation while yours goes into a pond. I assume you are less water stressed than they are in the Jordan valley. We also need a bigger reed bed than you do because you remove much of the BOD from and TSS from the waste stream when you catch and compost your solid waste, which we are not going to do, for now.

Thanks a lot for your reply. Of course there is not much that is new under the sun and I’d be surprised if our “wet composting” system was completely new and unknown. Saying that, the description in the AU govt. document you link to (at http://www.dlg.nsw.gov.au/DLG/Documents/information/onsite.pdf p101) bears almost no resemblance to the system we have constructed — it looks to me like another system designed by an engineer to solve an ecological problem. I haven’t seen a write-up of a really simple and cheap wet composting system either here or elsewhere. We have no compost auger, no compost extraction chute, no ventilation tube, no filter membrane, no drainage and aeration coils (and no dedicated outhouse); we have a shovel and a bed of branches. Like I say I’m not an expert, but all these manufactured systems seem to make something SOOO complicated that is really quite simple when you get down to it: keep the shit in the right conditions for long enough to break down. I strongly suspect that manufactured systems will never take off in majority-world conditions merely for cost reasons.

You know the local culture, I don’t, but in my experience (limited to Spain) people who have lived with animals for generations are not frightened of shit whether human or animal, often they have, if anything, too blasé an attitude and are likely to tolerate more unsanitary conditions than otherwise. The work involved in wet composting is far from arduous (scatter sawdust every few days; to shovel out finished compost every six months to a year.) Having said that, I accept that culturally, for most people, the less contact with shit, the better; which is a sane and sensible attitude, just one that needs to be tempered by saying, “yes, but we need to take responsibility for our own shit”. Which is true in so many ways!

It’s true to say that we are living in much less water-stressed conditions than in Jordan (most people are!) As has been suggested elsewhere, maybe the way to go in these conditions is not to use flush toilets in the first place. The question is, how far do we have to bend over backwards to appease the gods of Western progress?

Thanks for putting me straight on a few points — I didn’t know that septic tanks also function as anaerobic digesters, emitting methane gas, as someone else has pointed out, like biogas generators. If you could tap that, as Stephan has suggested below, you might have a useful byproduct while avoiding methane emissions, but maybe that’s too complicated. Thanks for not posting your first angry response, it’s more pleasant to be corrected in a civilized fashion!

http://www.permaculture.co.uk/readers-solutions/how-make-vermicomposting-flush-toilet
This is another worm composting system that I like very much. It is similar but considerably simpler than ours, having only one chamber in which, with a large worm population, there is no need to empty the chamber or scatter sawdust. It seems as if the worms aerate the compost and also digest it small enough that it will eventually pass out with the water. At least that seems to explain why it never needs to be emptied!

Hi Robert,
The way I am approaching this is that we start with people as they are. People in rural Jordan use squat toilets. These may or may not have a flush cistern. They can also just be flushed by dumping a bucket of water in after use. This is not a modern western imposed innovation. It’s the way most people do toilets anywhere in the ME and Asia, in my experience. Indeed the only culture I have come across (in my limited experience) that uses dry composting toilets was in Ireland in the old days, where they used to add lime into the latrines and then dig them out periodically and spread it on the fields.
In Ethiopia, where i have lived for the past 7 years, the standard toilet is a pit in ground with a squat plate on top. Flies can come and go as they please and make full use of the facilies. I’ve suffered enough typhoid and dysentery over the past years, and worse, had to experience my children suffering from them, to know that a blasé attitude towards sanitation can lead to big problems. Shit is not a total no-brainer. What you do on your own place is your business, but when you are designing for other people if something goes wrong and they end up getting sick then you are responsible. So what I want to do is design a system that works without the people living in the house having to make any concessions at all on their usual behaviour. A bit like you have had to do at your place, except that I am design a system which will not only be used by but also operated by “friends of the inlaws”. That includes the full range of ugly defects which emerge out of a traditional society when subjected to modernisation – for example toilet cleaner. So let’s say the lady of the household we are putting this system into has gotten used to cleaning the toilet with that stuff over the past 10 years. It keeps the toilet smelling clean and free of flies. She likes it that way. Remember that jawfa is swarming with flies, and they get everywhere. Out of the toilet and into the kitchen… Now we come along and say “don’t use that stuff,” we’ve put in a compost bog. “Use eco-toilet cleaner”. Eco-toilet cleaner is imported and three times the price of her locally manufactured stuff. She has to go to Amman to find it in some big mall somewhere. Then when the first bottle runs out she can’t go to Amman, because she has guests staying, there’s no petrol in the car and her husband is too busy at work etc. so she goes down to the local shop and buys the usual “toilet-duck”. Then the stuff in the compost box, which was composting away nicely, turns into a putrid stinking mess of foul slime which starts seeping through the mesh at the bottom of the chamber and blocks up the aeration spaces. Then it gets into the reed-bed and blocks that up too… so they get a back-flood into the garden, the flies have a field day and the stupid white man gets all the blame for putting them through all this.
So, I want a system that I am 100% sure is going to work. I am afraid I don’t consider this “bending over backwards to appease gods of western progress”. I consider this a pragmatic approach, because you can rest assured that if we screw this up nobody in town is going to be interested in working with us on any-thing like this in the future. But if it works and we get these people to feed their sheep from their waste water we may get some interest. One step at a time.
As for biogas that is the kind of step-two modification we would be able to make when step one has been demonstrated to work and people start getting interested in taking things further.
Anyway, thanks Robert and the others who have asked critical questions because it is necessary to evaluate and re-evaluate all options. However as things stand I still feel the sceptic tank to reed bed to UV zapper (which is only 20W) to drip irrigated beds is the best way to go, because it is the most robust and fail-safe system, requiring the least user commitment and behavioral modification. It may require more infrastructure but it requires less work to operate and presents less opportunities for disaster.

Thanks very much for your patience and for taking the time to explain the reasons behind your design. I have no experience working in places like Jawfa, and I’m sure you’re right about the drastic problems that could be caused by misuse of the system. Your horror story reminds me of a composting system I designed for the local school which was mis-used due to neglect by the school director who had promised to maintain it and ended up disgustingly anaerobic (yours truly had to dig the stuff out which was absolutely no fun, and it put paid to more ambitious plans for the school gardening club.)

I suppose I’ve got a bit of a bee in my bonnet about composting toilets, I guess it’s perhaps a moral thing, like “we should all deal with our own shit”, but you’re quite right, small and fail-safe steps are essential.

Good luck with your excellent project and I look forward to reading the triumphant followup sometime in the future.

I agree with Kama and Robert, some simplification may be required here. If you take the toilet water out of the equation by installing composting toilets, do you free up enough water for stock watering purposes? If so, you have grey water rather than black and you are not required to clean the waste water beyond the ‘C’ class for coliform counts as it is only used for irrigating fodder and not used to water stock. This gives you much more latitude in how you achieve the desired water quality. Also, are there any water-borne parasites that you need to look out for in the region? I look forward to reading more about the project as it sounds like you are breaking new ground here!

This DIY-wind-wheel is made completely out of spare parts (among others from a car wheel!). The picture is from a german DIY-booklet. For sure there is something similar available in other languages. The descriptions were translated from german by me. A used car generator produces at most about 300 W (diameter of the impeller: 1,8 m).

That is a good idea Stephen, but it goes a bit beyond what would be manageable in a single internship for now… but basically a bio-gas digester is just a big septic tank and i see no reason why it could not work. Again the system operators have to be able to manage it. I guess this would be a good option for phase II, if phase I goes well. Economically it would also make a lot of sense…

Alex,
I think you’re right on target with this project. I’ve lived in Jordan for 16 years now and I wholeheartedly agree with your assessment of cultural sensitivity. Add in religion, and a dry composting toilet is out of the question entirely, as washing “after” is a necessity of belief. Not to mention that where I live (about 40 km east of the GS) there is no carpenter anywhere, so sawdust for cover is unavailable even if you wanted to go for it :-)

Monica, thanks for the support. It’s reassuring to know that, as someone who’s lived there for many years, you agree with me. Incidentally it’s no problem to have a small amount of water enter a dry CT, indeed in a dry climate like that it may be beneficial because if it gets too dry there will be no breakdown, so the “estinja” water is actually beneficial. Anyway this is not really the issues, the issue is that people are going to be very hesitant to agree that they should handle their own manure at all, hence any form of CT, wet or dry is an idea that may take a while to gain acceptance. I have tried and failed time and again to get locals to use a CT in Ethiopia, maybe for different reasons, but the point is that it requires commitment, some measure of toilet discipline and basically some enthusiasm for the idea to get the CT to function well. And when it functions not-well then we are in trouble! Thanks, alex

Was curious about your reed bed. Is it likely the root system will plug up the gravel bed over time? Not sure if your reed roots grow wide and shallow or use all available space as they seem to do here in the NZ species. I think you also suggested some tree species might be planted in the channels?

The methane could be an altogether separate system, this one from the ARTI group in India won an Ashden award for sustainability and is very compact, using household food waste rather than sewage for a second use of waste resources, providing all the cooking gas a household needed, but much more compact than traditional sewage based systems.http://www.arti-india.org/index2.php?option=com_content&do_pdf=1&id=45

Hi Pete, thanks very much for your comment and this really useful info, that will really make things easier, since i do not know if the “flaut” technology is even available in Jordan. We are also looking into making the septic tank larger, maybe a 4-5m3 plastic tank for the first chamber with a 1000L IBC tank for the second. It is really taking me a long time to get the prices back on materials from Jordan and i cant afford to go there myself at the moment… Anyway, i am still hopeful we can pull this project off as we do have some funding opportunities in the making. I need to get together the data or a realistic budget though. Thanks for your info, it does help. Alex